2. THE SKELETAL SYSTEM The Appendicular Skeleton 2 pairs of
limbs and 2 girdles Pectoral (shoulder) girdle attaches upper limbs
Pelvic (hip) girdle secures lower limbs 3-Segmented limbs Upper =
arm Arm Forearm Hand Lower = leg Thigh Leg Foot
3. PectoralGirdle(Shoulder Girdle) Clavicle anterior: collar
bone Sternal end attaches to the manubrium medially Acromial end
articulates with the scapula laterally Scapula posterior: shoulder
blade
4. Scapulae: triangular, paired, but dontconnect in back (adds
thoracic flexibility)
5. Scapula Glenoid cavity articulates with the humerus Acromium
articulates with clavicle Coracoid process projects anteriorly
6. Upper extremity Arm or Brachium = upper arm Between shoulder
and elbow (humerus) Forearm or Antebrachium Radius & ulna Hand
includes: Wrist (carpus) Palm (metacarpus) Fingers (phalanges)
7. Arm Humerus is the only bone Head of humerus fits into
glenoid cavity of scapula Distal & medially, trochlea
articulates with the ulna Distal & laterally capitulum
articulates with the radius Medial & lateral epicondyles
8. Righthumerus,anterior view
9. Righthumerus,posterior view
10. Radius is thinner proximally, like a spool Forearm of
thread, and wide distally; ulna is slightly longer and looks like a
monkey wrench (supposedly!) 2 bones: articulate with each other
proximally and distally Interosseous membrane between them Ulna
Olecranon hinges with the humerus forming elbow Styloid process
distally Radius Contributes to wrist joint Styloid process anchors
a ligament to wrist (thumb side)
11. Right forearm bones,anterior view
12. Right forearm bones,posterior view
13. In the anatomical position, the radius is Left forearm
lateral (thumb side); with pronation the palm faces posteriorly and
the bones cross prone Anatomical Prone: body lying face down
position Suppine: body lying face up (you can remember prone if you
think about how you would fall forward onto your face if you passed
out)pronation moves the forearm into theprone position and
supination movesit back to the anatomical position
14. Proximal and distal joints of the forearm proximal
ulna
15. Hand Proximal is wrist 8 carpal bones Palm of hand - 5
metacarpals Fingers (or digits) consist of miniature long bones
called phalanges: thumb (pollex) has 2; fingers have 3: proximal,
middle, distal Right hand, 2 views:
16. Pelvic Girdle(Hip Girdle) Strongly attached to axial
skeleton (sacrum) Deep sockets More stable than pectoral (shoulder)
girdle Less freedom of movement Made up of the paired hip bones
Bony pelvis is basin-like structure: hip bones plus the axial
sacrum and coccyx
17. Hip bone (os coxae): 3 separate bones in childhood which
fuse Ilium Ischium Pubis
18. Ilium ilium Iliac crest Anterior superior iliac spine
Greater sciatic notch Forms part of acetabulum (hip socket) ilium
which receives ball-shaped head of femur
19. Ischium Body Ramus Ischial spine ischium Ischial tuberosity
Part of socket ischium
20. Pubis Joins medially in pubic symphysis pubis Forms
obturator foramen (large hole) with ischium Part of socket
pubis
21. Hip bones with labels
22. False (greater) and true (lesser) pelvisLigaments
23. Pelvis and childbearing Male/female differences Large &
heavy vs light & delicate Heart shaped pelvic inlet vs oval
Narrow deep true pelvis vs wide & shallow Narrow outlet vs wide
Less than 90 degree pubic arch vs more than 90 degree Birth canal
changes shape as baby descends: head turns Higher:pelvic inlet
(brim) - side to side largest Lower: pelvic outlet - largest in AP
direction
25. Thigh Femur is largest, longest and strongest bone in the
body Head fits in socket (acetabulum) of pelvis Neck is weakest
Greater trochanter Distal: lateral & medial condyles and
epicondyles Patella: sesmoid bone
26. Right femur,anterior view
27. Right femur,posterior view
28. Leg Tibia: shin bone Medial and lateral condyles Tibial
tuberosity Distal medial malleolus (medial ankle) Fibula Distal
lateral malleolus (lateral ankle) Interosseous membrane
29. Right lowerleg, anterior view
30. Foot Tarsus: 7 tarsal bones Talus: articulates with tibia
and fibula anteriorly and calcaneus posteriorly Calcaneus: heel
bone Smaller cuboid, navicular, and 3 cunieforms (medial,
intermediate and lateral) 5 metatarsals 14 phalanges Great toe is
hallux
31. Right foot, superior (dorsal) view and inferior (plantar)
view
